Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10896911 | Cancer Detection and Prevention | 2005 | 8 Pages |
Abstract
Background: We investigated risk factor patterns for subtypes of breast cancer characterized by joint estrogen receptor (ER) and progesterone receptor (PR) status in a hospital-based case-control study. Methods: ER and PR tumor status were determined immunohisotchemically. Risk factors of interest were entered into a multiple polychotomous logistic regression model simultaneously; odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Using this model, cases in the four tumor subtypes (ER+PR+, ERâPRâ, ER+PRâ, ERâPR+) were compared simultaneously to controls. A Wald test for heterogeneity across the four subtypes was conducted, as well as a case-case comparison between the two most biologically disparate subtypes, ER+PR+ and ERâPRâ. Results: The receptor status distribution was as follows: 33% ER+PR+, 34% ERâPRâ, 20% ER+PRâ, and 13% ERâPR+. Among 317 cases and 401 controls, we found significant heterogeneity across the four tumor subtypes for older age at first full-term pregnancy (p = 0.04) and post-menopausal status (p = 0.04). For older age at first full-term pregnancy, an elevated risk was found for the ER+PRâ subtype (OR = 2.5; 95% CI: 1.2-5.1). For post-menopausal status, elevated risks were found for both the ER+PR+ (OR = 2.4; 95% CI: 1.1-4.9) and ER+PRâ (OR = 7.2; 95% CI: 2.4-21.7) subtypes. From the case-case comparisons, we found that cases, who had consumed alcohol for more than 1 year were 3.4 times more likely to have ER+PR+ tumors than ERâPRâ tumors (95% CI: 1.4-8.4). Conclusions: Certain breast cancer risk factors may vary by ER and PR status, and joint ER/PR status should be taken into account in future studies of risk factor estimates.
Keywords
Related Topics
Life Sciences
Biochemistry, Genetics and Molecular Biology
Cancer Research
Authors
Jennifer A. PhD, Theodore R. PhD, Shelia H. PhD, Tongzhang DSc,